How to choose a firmware partner

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How to choose a firmware partner:

Ask if it's policy to enable the watchdog timer. The correct answer is
"no".

If they say "yes" then you know that their code is dodgy, and/or their
hardware is vulnerable and if the WDT is not going off occassionally,
it probably will after the next modification.

Cheers
Robin

Re: When to reject possible contracts (was How to choose a firmware partner)

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Unless you absolutely, positively can't afford not to take a contract,
anyone who comes up with this sort of pig-ignorant over generalisation from
a limited knowledge base is someone you don't want to work for.  The mere
idea that this can be simplified to a yes or no question indicates the
questioner's willingness to micro-manage a complex technical decision and
proclaim edicts on subjects that are beyond his knowledge and understanding.
No good can come from working with such an arrogant simpleton.

Sorry, not for me,
Alf



Re: When to reject possible contracts (was How to choose a firmware partner)
On Wed, 26 May 2004 20:55:11 +1000, the renowned "Unbeliever"

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Before going for a drive with anyone, ask them if they have insurance
or, if not, if they would sign up for it it if it was free. If they
say "yes" then you know they are terrible drivers and/or their car is
in dangerous condition.

Best regards,
Spehro Pefhany
--
"it's the network..."                          "The Journey is the reward"
snipped-for-privacy@interlog.com             Info for manufacturers: http://www.trexon.com
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Re: How to choose a firmware partner
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Utter twaddle.


Watchdogs are not there to protect against dodgy code and/or unduly
"vulnerable" hardware. They're there because, ultimately, *all* hardware is
vulnerable. It's just a question of degree. If you don't believe me, equip
yourself with a Schaffner and try dumping a fast-rise time 2kV spike into
nearby metalwork...

Robin, I'm afraid your ignorance is showing.

Steve
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: How to choose a firmware partner
On Wed, 26 May 2004 12:30:02 +0100, "Steve at fivetrees"

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I bet he doesn't even re-write his I/O Configuration registers...

Regards,

                               -=Dave
--
Change is inevitable, progress is not.

Re: How to choose a firmware partner
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The watchdog timer is a fairly recent invention, millions of older systems run
fine without them.

Re: How to choose a firmware partner
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is
equip
run

It's exactly as old as embedded microprocessors. (I know. I was there.) It's
dumb having one without the other.

Steve
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: How to choose a firmware partner
On Wed, 26 May 2004 17:12:46 +0100, "Steve at fivetrees"

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No, it's much older than embedded microprocessors.

--
Al Balmer
Balmer Consulting
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Re: How to choose a firmware partner
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systems
It's

I'm intrigued! I only came across them in the context of embedded micros
(late '70s), but on reflection I can imagine they'd be useful thingies in
non-embedded contexts. However, I presume still within the realms of
hardware/software integration? Pray tell!

Steve
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: How to choose a firmware partner
On Wed, 26 May 2004 20:01:46 +0100, "Steve at fivetrees"

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We used them in the mid to late 60's on process control systems. On a
dual system, the watchdog did two things - it switched the process
control bus to the backup computer and rebooted it. The control
database was piped once per second from the control computer to the
backup on a high-speed core-to-core link, and the reboot took less
than a second. This was from a head-per-track disk, and the biggest
system had a whole megabyte of memory, so it didn't take long :-)

On single-processor systems, we sometimes used a sort of long-period
mechanical watchdog. If there was a power interruption, the system
would recover when power was restored, and the watchdog would enable
the decision as to whether to pick up the process where it left off,
or stay in failsafe and yell for an operator.

--
Al Balmer
Balmer Consulting
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Re: How to choose a firmware partner
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Impressive!

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My main background is also in process control (mainly temperature control).
From working in Chicago in the early 80s I recall that "watchdogs" (or was
it "policemen"?) were mandatory (insurance-wise) on certain processes in
certain states, but these were simply over-temperature/pressure failsafes...
or have I got that all backwards? A lot of neurons have flowed under the
bridge since...

Steve
(older, wiser, balder)
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: How to choose a firmware partner


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A full megabyte....in the 60's?....that's pretty big.  I programmed on
WWMCCS GE/Honeywell mainframes in the early 80's that didn't have a full
megabyte of magnetic core memory.


Re: How to choose a firmware partner

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I would be interested (and surprised) to know which
computer had a megabyte of core in the 60's.
see http://www.crowl.org/Lawrence/history/computer_list
to help "refresh your memory" (bad pun).
I worked on Elliot 920B's (not on the list) perhaps
because it was military??

Phil



Re: How to choose a firmware partner

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on
full

I would like to know as well.  I worked on Honeywell 6000's and when I
say early 80's, I mean July of 1980 and on.  IIRC (and I think I do ;-)
they had about 128K words of core, and each word was 36 bits.  They
really didn't use "bytes" allot, as the native character set was BCD (6
bits/char).  They also had ASCII support (sort of ;-) where there were 4
"must be zero" bits per word.  Bits were numbered from left to right,
IOW Bit 0 was the MSB.  The first 64K words was the "hard core monitor"
or HCM and was the nucleus of the OS.  The machine was an evolution of
the GE 635 which was a bit simpler, and before my time.  I could go on,
but I'll stop before I bore you to death.  I really miss that
architecture from a low level point of view, it was a real beauty in
it's own right.  :-(  For real-time response and transaction processing
they always kicked IBM's butt.  Shows the power of a good marketing
program.


Re: How to choose a firmware partner


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I
;-)
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Cool, it's nice to meet someone that actually worked with this stuff
before.  I was beginning to think that everyone who had was dead now, or
worse yet French.  ;-)


Re: How to choose a firmware partner
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Huh? Why French?

Steve
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: How to choose a firmware partner
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IIRC RCA sold out to GE sold out to Honeywell sold out to Bull.

--
Chuck F ( snipped-for-privacy@yahoo.com) ( snipped-for-privacy@worldnet.att.net)
   Available for consulting/temporary embedded and systems.
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Re: How to choose a firmware partner

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stuff
now, or

GE was long out of the picture before Bull took over from Honeywell.
Most of the conversion from GE to Honeywell involved removing the E from
all the documentation.  GECOS became GCOS, GEMAP -> GMAP etc...

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AIUI Honeywell started it and partnered with Bull during the process.

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True, AIR they made some of the processors for the DPS machines.


Re: How to choose a firmware partner
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    In the very late '60s I worked on a UNIVAC 1110 which had that much
memory but I can't say now if it was core or semi.

        Norm


Re: How to choose a firmware partner

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In the 60's, it must have been core.

In the mid-70's, the PDP-11/70 physical address space was 4 MB, but
with original DEC core modules, two full size cabinets would be needed
to hold all those core modules. However, connecting all these would
have violated the memory bus length limitation. Thus, with core
memory, the maximum memory capacity would have been IIRC 1 or 2 MB.

In 1977 or 1978 Intel sold semiconductor memory  modules built around
8 kbit x 1 DRAMs. With these modules 4 MB would fit into one cabinet
and the memory bus length was within specification.

In those days the largest DRAMs Intel made was 16 kbit x 1, so
apparently they used those 16 kbit DRAMs with a defect in one half of
the memory plane and used as 8 kbit devices in their own modules.

In those days DRAMs suffered from soft errors, apparently due to alpha
particles emitted by the plastic package, thus the modules had ECC
instead of parity, which was the norm for core memories in those days.
Operators manually logged the error status registers on the module
before resetting the counters. Frequent failures in a particular chip
required replacing it sooner or later.

While computer systems with 1 MB of memory could have been done in
1975/76 using 4 kbit x 1 (requiring 2000-2500 DRAMs), but I doubt that
making 1 MB with 1kbit x 1 SRAMs (requiring 8000-10000 chips) would
have been very practical due to the high power consumption.

Paul
 
 

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